The nature of the unresolved extragalactic soft CXB

Abstract

In this paper we investigate the power spectrum of the unresolved 0.5-2 keV CXB with deep Chandra 4 Ms observations in the CDFS. We measured a signal which, on scales >30", is significantly higher than the Shot-Noise and is increasing with the angular scale. We interpreted this signal as the joint contribution of clustered undetected sources like AGN, Galaxies and Inter-Galactic-Medium (IGM). The power of unresolved cosmic sources fluctuations accounts for \sim 12% of the 0.5-2 keV extragalactic CXB. Overall, our modeling predicts that \sim 20% of the unresolved CXB flux is made by low luminosity AGN, \sim 25% by galaxies and \sim 55% by the IGM (Inter Galactic Medium). We do not find any direct evidence of the so called Warm Hot Intergalactic Medium (i.e. matter with 10^5K<T<10^7K and density contrast δ <1000), but we estimated that it could produce about 1/7 of the unresolved CXB. We placed an upper limit to the space density of postulated X-ray-emitting early black hole at z>7.5 and compared it with SMBH evolution models.

15 pages, 9 figures, accepted by MNRAS

References in corpus (13)

• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• The XMM-Newton wide-field survey in the COSMOS field: VI. Statistical properties of clusters of galaxies
• The XMM-Newton wide-field survey in the COSMOS field. The point-like X-ray source catalogue
• The 2dF-SDSS LRG and QSO Survey: QSO clustering and the L-z degeneracy
• Quasistars: Accreting black holes inside massive envelopes
• The Evolution of Obscuration in AGN
• The Co-Formation of Spheroids and Quasars Traced in their Clustering
• High redshift quasars in the COSMOS survey: the space density of z>3 X-ray selected QSOs
• XMM-Newton observations of the Lockman Hole: X-ray source catalogue and number counts
• The X-ray Properties of Early-Type Galaxies in the Extended Chandra Deep Field-South
• The X-ray luminosity function and number counts of spiral galaxies
• X-Ray Emission from the Warm Hot Intergalactic Medium
• Warm-hot intergalactic medium contribution to baryonic matter

Cited by in corpus (21)

• The Chandra COSMOS legacy survey: Energy Spectrum of the Cosmic X-ray Background and constraints on undetected populations
• Ultra-deep catalog of X-ray groups in the Extended Chandra Deep Field South
• Detecting shocked intergalactic gas with X-ray and radio observations
• Faint progenitors of luminous $z\sim 6$ quasars: why don't we see them?
• Highlights and Discoveries from the Chandra X-ray Observatory
• Population III X-ray Binaries and their Impact on the Early Universe
• Cross-correlation between X-ray and optical/near-infrared background intensity fluctuations
• Exploring the cosmic dawn and epoch of reionization with 21cm line
• Can AGN and galaxy clusters explain the surface brightness fluctuations of the cosmic X-ray background?
• New metrics to probe the dynamical state of galaxy clusters
• X-ray and Sunyaev-Zeldovich properties of the WHIM
• Maximal X-ray feedback in the pre-reionization universe
• Studying the ICM in clusters of galaxies via surface brightness fluctuations of the cosmic X-ray background
• Lensing and the Warm Hot Intergalactic Medium
• The Advanced X-ray Imaging Satellite
• Cosmology and Astrophysics with the Diffuse eRASS1 X-ray Angular Power Spectrum
• Suzaku Observations of the old pulsar wind nebula candidate HESS J1356-645
• Astrophysical uncertainties challenge 21-cm forecasts: A primordial black hole case study
• Spatial Power Spectral Analysis of the Suzaku X-ray Background
• Self-consistent population synthesis of AGN from observational constraints in the X-rays
• Revisiting Galaxy Cluster Scaling Relations through Dark Matter-Gas Coherence: Scatter Dependence on Dynamical State